Venture capital firm Benchmark, one of Uber's early investors, is among the investors in talks to sell shares, unnamed sources told Bloomberg. Such a deal could provide new money into the ride-hailing company, Bloomberg added, citing the sources.

However, a source familiar with Softbank's plans said it is not in discussions to purchase Uber stock.

Uber was not immediately available to comment on the report. Investor TPG, which has board membership at Uber, declined to comment.

CNBC reported last month that Uber insiders are seeking to sell shares. In fact, Uber execs think allowing some employees to do so might help boost morale inside the company. The call will be up to Uber's board of directors, since most of the senior staff has departed the company in recent weeks.

A sale would mark another massive change in the relationship between Uber and Benchmark, which reportedly helped lead the ouster of CEO Travis Kalanick earlier this year. Bill Gurley, long-time Uber board member, was replaced on Uber's board this summer.

CEO Masayoshi Son has proclaimed an ambitious vision spanning over the next century to invest in emerging technologies. To that end, the Japan-based conglomerate tied up with backers like Apple and Oracle's Larry Ellison. It's unclear if this deal would be related to that fund.